Background: The purpose of the present study is to investigate the effect of Chronic L-Carnitine Supplementation on Exercise Performance, Blood Lactate, and Exercise-Induced Oxidative Stress in Resistance-Trained Males Materials and Methods: We examined 35 resistance-trained (1y) male participants (25±2y, 79.8±8.9 kg, 16.1±5.53% body fat) for 9-wk of L-carnitine supplementation in conjunction with resistance training on exercise performance, blood lactate, and exercise-induced oxidative stress. Randomized, placebo-controlled, double-blind treatment of a (1) no intervention, no supplement Control (CON, n=12), (2) maltodextrose Placebo (PLA, 2 g/d, n=11) or (3) L-carnitine (LCR, 2 g/d, n=12). Exercise performance, post-exercise blood lactate (BL) and oxidative stress markers were analyzed at weeks 3, 6, and 9. The PLA and LCR groups followed a specific resistance training program (4 d/w, upper body/lower body split) for a 9-wk. Data were analyzed by GLM and presented as mean (SD) or change (95% CI). Primary outcomes were total lifting volume for the bench (BP) and leg press (LP). Results: The results a significant increase in BP lifting volume at wk-6 (139 kg, 95% CI 49.1, 230) and wk-9 (238 kg, 95% CI 132, 343) for LCR. Similar results were observed for LP. We also observed a significant increase in Wingate mean power (63.4 W, 95% CI 30.5, 96.3) and peak power (239 W/kg, 95% CI 104, 374) at wk-9 for LCR as well as a significant reduction in post-exercise BL levels and oxidative stress responses. No differences were observed in body composition. Conclusion: These findings indicate that LCR supplementation improves exercise performance and attenuates the blood lactate and oxidative stress response to resistance training. پرونده مقاله

Background: The aim of this study was to examine the effects of a tapering period with creatine supplementation on hormonal responses of men football players. Materials and Methods: The study sample included 18 male soccer players of the first division league (mean age: 18.77 ± 1.26 years, height: 174.5± 5.77 cm, and weight: 64.07± 6.99 kg) that were in the specific conditioning period who were randomly divided into two equal groups: Taper alone (n=9) and Taper with creatine supplementation (n=9). The levels of blood hormonal parameters including testosterone, cortisol and testosterone to cortisol ratio (T/C) were measured before and after the tapering period (10 days). Paired t-test and independent T-test was used to examine the differences within and between groups, respectively. Results: The results showed that the cortisol levels in the post-test compared to the pre-test decreased significantly in both groups (p≤0.05) ; While, there was no significant difference in testosterone and T/C (p≥0.05). Also, no significant difference was observed in the levels of testosterone, cortisol and T/C between the two groups. Conclusion: The taper period can reduce the cortisol levels of male soccer players, but creatine consumption has no significant effect on the levels of cortisol, testosterone and T/C ratio in the taper period. پرونده مقاله